Carl Schorlemmer, LL.D., F.R.S

Abstract

CARL SCHORLEMMER having been my friend and colleague in Owens College for more than thirty years, it is with a sad pleasure that I take up my pen to record in the columns of NATURE some few details of his character and work. He had not, like his predecessor Dittmar, been a fellow student with me in Heidelberg, but had worked at chemistry in Darmstadt, where he was born, and at Giessen. In 1858 Dittmar, who up to that year had been my private assistant, obtained the College appointment of Demonstrator, and he strongly urged me to offer his vacant post to his friend Schorlemmer, a young man of great promise. From the time of his arrival in Manchester until the day of his death I do not recollect that in all the intercourse of those years Schorlemmer and I ever had a single serious difference. Whilst my private assistant he and I examined the relation which the aqueous acids exhibit as regards boiling point and composition, and I remember well the difficulties we had to contend with in distilling fuming nitric and hydrofluoric acids under pressure, and I also remember how successfully he met them. Once, I know, he got some fuming hydrofluoric acid on his hand, and he bore the scar of the serious burn to the end. This work with me was his apprenticeship. In a short time Dittmar left us, and Schorlemmer took his place as the official Laboratory Assistant, and as we had not many students at that time, he had leisure to begin the hydrocarbon work which has placed his name high in the list of organic chemists of the century. In 1861 the late Mr. John Barrow, of the Dalton Chemical Works, Gorton, brought me a sample of the light oils which he had obtained in the distillation of cannel coal. At that time our knowledge of the chemical composition of the low-boiling coal-oils was very incomplete, and I urged Schorlemmer to undertake the investigation. This was the beginning of the work which led to a result which altogether modified the existing ideas concerning the constitution of the paraffin hydrocarbons, and paved the way for the sound foundation upon which the organic portion of our science has since been successfully laid. In order to appreciate Schorlemmer's results let us for a few moments glance at the position of the question when he commenced work. Before 1848 the only known member of the paraffin series of hydrocarbons, was methane CH₄. In the above year the researches of Kolbe on the electrolysis of the fatty acids, and of Frankland on the isolation of the alcohol-radicals, opened out new fields yielding a rich harvest. Each molecule of these latter hydrocarbons was supposed to contain two molecules of the radical methyl being represented as , whilst together with these a second series of hydrides was believed to exist, ethyl hydride standing in the same relation to the radical as an alcohol does to an ether. The truth of this view seemed confirmed by Wurtz's discovery of the existence of the so-called mixed radicals in which two molecules of different hydrocarbons, such as ethyl and amyl r2u5 occurred. How was this question to be settled? Schorlemmer at once seized upon the correct method of solution and carried it out successfully. If, said he, the radical methyl is identical with hydride of ethyl not only must these two bodies possess the same properties, but both bodies must yield the same product, viz., ethyl chloride, on treatment with chlorine. This identity he proved, not only in the above—the most simple case—but in the more complicated cases of ethyl-amyl and of di-amyl as these hydrocarbons yielded respectively chloride of heptyl and chloride of decatyl, C₇H₁₂C1. and C_1OH₂₁C1. It is difficult to overrate the importance of this apparently simple discovery. It laid for ever the ghost of the existence of two sets of isomeric hydrocarbons of the paraffin series, and paved the way for Kekulé's theory of carbon combination, upon which the whole modern theory of organic chemistry is based. So to Schorlemmer belongs the credit of placing in position the foundation-stone of our science. And at once his name became known as a master wherever chemistry is studied; so that in 1871 the Council of the Royal Society admitted him to the Fellowship at once, an honour conferred nowadays on few.